Field of the Invention
The present invention relates to a carrier, a planetary gear mechanism, a transmission, and a working vehicle.
Planetary gear mechanisms and a plurality of clutches, which are for switching between connection and disconnection of rotation elements in the planetary gear mechanisms, are provided in a transmission. For example, a transmission which is provided with a first planetary gear mechanism and a second planetary gear mechanism is disclosed in Japanese Unexamined Patent Application Publication No. 2006-329244. In this transmission, connection and disconnection of a carrier of the second planetary gear mechanism and a housing is switched using a first clutch. In addition, connection and disconnection of a carrier of the second planetary gear mechanism and a ring gear in the first planetary gear mechanism is switched using a second clutch.
Not only planetary gears in the second planetary gear mechanism but also the first clutch and the second clutch are attached to the carrier described above. In addition, since a sun gear engages with the planetary gears, the sun gear is arranged to be close to the carrier. Furthermore, a piston for driving the first clutch and a piston for driving the second clutch are also arranged. It is preferable that these plurality of components are arranged in a compact manner in the surroundings of the carrier in order for the size of the transmission to be reduced.
In addition, a drive circuit for supplying hydraulic fluid to the pistons is necessary in order for the pistons to be driven using hydraulic pressure of the hydraulic fluid. Furthermore, a lubricating circuit for lubricating each of the clutches is also necessary. However, when the plurality of components described above are arranged in a compact manner in the surroundings of the carrier, it is not easy for the drive circuit and the lubricating circuit to be arranged to avoid these components. In addition, there is a problem in that the structure of the transmission becomes complicated and ease of assembly of the transmission is reduced due to arranging of the drive circuit and the lubricating circuit.
The problem of the present invention is to propose a carrier, a planetary gear mechanism, a transmission, and a working vehicle where it is possible to improve ease of assembly by suppressing complicating of the structure of the transmission while also reducing the size of the transmission.
A carrier according to a first aspect is a carrier to which a first clutch and a second clutch are attached and which is for supporting a planetary gear in a planetary gear mechanism. The carrier is provided with a circular plate section, a cylinder section, a planetary gear arrangement section, a first hydraulic fluid flow path, and a second hydraulic fluid flow path. The circular plate section has a first support section for supporting one end of a support pin for the planetary gear. The cylinder section is arranged to be separated from the circular plate section in the axial direction of the circular plate section. The cylinder section has a second support section for supporting the other end of the support pin for the planetary gear, a first clutch attachment section for attaching to the first clutch, a second clutch attachment section for attaching to the second clutch, and a piston attachment section for attaching to a piston for driving the second clutch. The planetary gear arrangement section is arranged between the circular plate section and the cylinder section in the axial direction. The planetary gear arrangement section has a space where the planetary gear is arranged. The first hydraulic fluid flow path has a first inlet which is provided in the circular plate section. The first hydraulic fluid flow path is provided at an inner section of the circular plate section and the cylinder section. Hydraulic fluid for lubricating the first clutch is supplied from the first inlet to the first clutch attachment section via the first hydraulic fluid flow path. The second hydraulic fluid flow path has a second inlet which is provided in the circular plate section. The second hydraulic fluid flow path is provided at an inner section of the circular plate section and the cylinder section. Hydraulic fluid for driving the piston is supplied from the second inlet to the piston attachment section via the second hydraulic fluid flow path.
In this case, the carrier supports not only the first clutch and the second clutch but also supports the piston. For this reason, it is possible for the transmission to be reduced in size and it is possible to simplify the structure of the transmission compared to a case where the piston support structure which is separate to the carrier is provided in the vicinity of the carrier.
In addition, it is possible for the second hydraulic fluid flow path, which is for driving the piston in the second clutch, to be provided in an inner section of the carrier since the carrier has the piston attachment section. Furthermore, it is possible for the first hydraulic fluid flow path, which is for lubricating the first clutch, to be provided in an inner section of the carrier since the carrier has the first clutch attachment section. Due to this, it is possible to simplify the structure of the transmission and it is possible to improve ease of assembly of the transmission.
Furthermore, the first inlet and the second inlet are both provided in the circular plate section. That is, the first inlet and the second inlet are arranged on the opposite side with regard to the planetary gear arrangement section and not in the cylinder section to which the first clutch, the second clutch, and the piston are attached. For this reason, it is possible to easily arrange the member for supplying hydraulic fluid to the first inlet and the second inlet by avoiding interference with the first clutch, the second clutch, the piston, and a sun gear which engages with the planetary gear or with components which relates to these.
It is preferable that the first inlet and the second inlet be arranged to be separated from each other in the axial direction of the carrier. In this case, it is possible to easily connect the hydraulic circuit in the separate systems with the first inlet and the second inlet. That is, it is possible to easily connect the hydraulic circuit which is appropriate for lubricating the clutch and the hydraulic circuit which is appropriate for driving the piston respectively with the first inlet and the second inlet.
It is preferable that the circular plate section have a hole which penetrates through the circular plate section at the center of the circular plate section. At least one of the first inlet and the second inlet is provided at an inner surface of the hole. In this case, since a shaft member, where a flow path is provided in an inner section, passes through the hole, it is possible for hydraulic fluid to be supplied to at least one of the first inlet and the second inlet via the flow path inside the shaft member.
It is preferable that the first hydraulic fluid flow path have a first upstream side flow path and a first downstream side flow path. The first upstream side flow path is provided in an inner section of the circular plate section and connects the first inlet and the first support section. The first downstream side flow path is provided in an inner section of the cylinder section. The first downstream side flow path connects the second support section and the first clutch attachment section. In this case, it is possible for hydraulic fluid to be supplied from the first inlet to the piston attachment section due to the first upstream side flow path and the first downstream side flow path being connected using a flow path which is provided in an inner section of the support pin.
It is preferable that the planetary gear arrangement section have a linking section which links the circular plate section and the cylinder section. The second hydraulic fluid flow path has a second upstream side flow path, a second downstream side flow path, and an intermediate flow path. The second upstream side flow path is provided in an inner section of the circular plate section. The second upstream side flow path is connected with the second inlet. The second downstream side flow path is provided in an inner section of the cylinder section. The second downstream side flow path is connected with the piston attachment section. The intermediate flow path is provided in an inner section of the linking section. The intermediate flow path connects the second upstream side flow path and the second downstream side flow path. In this case, it is possible for hydraulic fluid to be supplied from the second inlet to the piston attachment section via the second upstream side flow path which is in an inner section of the circular plate section, the intermediate flow path which is in an inner section of the linking section, and the second downstream side flow path which is in an inner section of the cylinder section.
It is preferable that the first hydraulic fluid flow path has a plurality of outlets, a first flow path, a merging flow path, and a plurality of second flow paths. The plurality of outlets are connected with the first clutch attachment section. The first flow path extends in the radial direction of the cylinder section. The merging flow path is connected with the first flow path and extends in the circumferential direction of the cylinder section. The plurality of second flow paths connect the merging flow path and the plurality of outlets. In this case, hydraulic fluid is efficiently sent to the merging flow path using the centrifugal force of the carrier since the first flow path extends in the radial direction of the cylinder section. Hydraulic fluid is sent to the plurality of second flow paths by being dispersed in the merging flow path. Then, hydraulic fluid is supplied from each of the plurality of second flow paths to the first clutch via the plurality of outlets. Due to this, it is possible to uniformly supply hydraulic fluid to the first clutch over a wide range.
It is preferable that the cylinder section has a first cylinder section and a second cylinder section. The first cylinder section includes the second support section and the piston attachment section. The second cylinder section is connected with the first cylinder section. The first clutch attachment section is provided on the outer circumference of the second cylinder section. The second clutch attachment section is provided on the inner circumference of the second cylinder section. In this case, it is possible for the first clutch, the second clutch, and the piston to be arranged in a compact manner in the vicinity of the carrier.
It is preferable that the first cylinder section and the second cylinder section be separate bodies. In this case, it is possible to easily manufacture the carrier even when the shape of the carrier becomes complicated.
A planetary gear mechanism according to a second aspect is provided with a sun gear, a planetary gear, the carrier described above, and a ring gear. The planetary gear engages with the sun gear. The carrier supports the planetary gear. The ring gear engages with the planetary gear and is provided so as to be able to rotate.
A transmission according to a third aspect is provided with a first clutch, a second clutch, and the planetary gear mechanism described above.
A working vehicle according to a fourth aspect is provided with an engine, a hydraulic pump, a working implement, a travel apparatus, and the transmission described above. The hydraulic pump is driven using the engine. The working implement is driven using hydraulic fluid which is discharged from the hydraulic pump. The travel apparatus is driven using drive force from the engine. The transmission transfers drive force from the engine to the travel apparatus.
According to exemplary embodiments of the present invention, it is possible to propose a carrier, a planetary gear mechanism, and a working vehicle where it is possible to improve ease of assembly by suppressing complicating of the structure of a transmission while also reducing the size of the transmission.